1. Field of the Invention
The present invention is directed to a hearing aid of the type having a calculation unit, employing a neural structure, in order to generate control signals for controlling an amplifier and transmission stage, connected between an input and an output of the hearing aid, for modifying an input signal.
As used herein "signal" means the curve of one or more physical quantities and one or more measuring points over time; each signal can thus be composed of a bundle of individual signals.
2. Description of the Prior Art
European Application 0 712 263 discloses such a hearing aid of the above type wherein a neural structure is utilized in order to either modify the signal transmission characteristic of an amplifier and transmission means or to select a set of parameters from a parameter memory that influence the signal transmission characteristic.
European Application 0 712 261, corresponding to co-pending U. S. application Ser. No. 08/515,907, filed Aug. 16, 1995, discloses a similar hearing aid wherein, however, the signal path is conducted through the neural structure, so that the signals transmitted from at least one microphone to an earphone can be directly processed by the neural structure.
European Application 0 712 262 discloses a hearing aid wherein an automatic gain control (AGC) circuit has a controller based on the principle of a neural structure allocated to it.
The hearing aids disclosed in these published applications, however, only provide that the neural structure be realized in analog circuit technology. Deriving therefrom is the problem of a high circuit-oriented outlay that has a disadvantageous influence particularly because of the miniaturization required in hearing aids.